The present invention relates to an electromagnetic actuation device according to the preamble of the main claim. A device of this type is known from the applicant's WO 2010/063394 A1 and describes a core unit having a coil means, which core unit is constructed for interacting with armature means that are movably guided relatively to the core unit, as a reaction to an energising of the coil means. The armature means have a plurality of tappet units, which in each case have permanent magnet means at the end thereof that are directed towards the core unit. As a reaction to the energising of the core unit and the polarity chosen for this energising, the possibility therefore arises to selectively drive individual tappet units, in that the core unit repels a respective one of the permanent magnet units by means of the electromagnetically generated flux. Thus, depending on the configuration of the device, a contra-rotating movement of a pair of tappet units for example can also be realised.
An electromagnetic actuating device for camshaft adjustment has become popular, especially in the context of internal combustion engines for automobiles. A technology of this type makes it possible in particular to engage by means of a tappet unit driven in the previously described manner into an adjustment slot constructed in a manner suitable for interaction with the tappet end and thus to effect the camshaft adjustment. In this case, an adjustment groove of this type also enables the retraction of an extended tappet unit back to a stop position on the core unit after ending energisation.
It is additionally to be assumed to be known from the prior art, for example the above-introduced prior art forming the generic type, that a plurality of tappet units is used for camshaft adjustment. Thus, it is for example known to use a first of the tappet units for camshaft adjustment along a first axial direction and a second of the tappet units for axial retraction of a correspondingly adjusted camshaft unit. In this case, it is on the one hand to be assumed to be known to assign each of these tappet units its own electromagnetic actuator, these actuators then being clocked or energised according to a respective purpose. The cited prior art according to WO 2010/063394, which forms the generic type, furthermore already described the possibility, as a reaction to the energising of only a single coil (or an arrangement of coils), of moving a plurality of tappet units simultaneously or together. In particular, the possibility is also disclosed here, of moving the plurality of tappet units (that is to say for example a pair of mutually adjacent guided tappets) simultaneously and in the same direction, wherein this presumes however, that in accordance with the polarity conditions at the described arc- or U-shaped yoke region, appropriate selected or assigned polarity conditions of the permanent magnet means must apply relatively to a respective yoke core section.
Accordingly, realisation of a multiple tappet technology is complex and furthermore entails difficulties in exact assignment during assembly.